Medical liquid container with tactile sterility indicator and method of testing container

ABSTRACT

A container for sterile medical liquids that has a double cap sealed closure system. A deformable thermoplastic top wall of an outer cap is spaced a distance from a top wall of an inner cap when properly sterilized. Thumb pressure on the outer cap brings the top walls of the two caps into contact. This contact provides an instant tactile test for determining that the container has been through a steam sterilization cycle and there are no leaks at the inner and outer cap seals with the bottle.

United States Patent [1 1 1111 3,923,179 Choksi et a]. 451 2, 1975 [5 1 MEDICAL LIQUID CONTAINER WITH 3,025,988 3/1962 Williams 215/32 x TACTILE STERILITY INDICATOR AND g =L1 2 55/ at 13 et a METHOD OF TESTING CONTAINER 3,443,711 5/l969 Olson 215/7 [75] Inventors: Pradip V. Choksi, North Hollywood; .5 184 6/l9 Guala 2 R B st idl S l B h b h f 3,730,372 5/1973 Komendowski 215/30 Calif.

Assignee: American Hospital Supply Corporation, Evanston, 111.

Filed: Mar. 7, 1973 Appl. No.: 338,661

U.S. Cl 215/203;2l5/1 R; 2l5/DIG. 3;

215/251 Int. Cl B65d 55/02 Field of Search..... 215/46 A, 42, 37 R, DIG. 3,

Primary ExaminerHerbert F. Ross Attorney, Agent, or FirmLarry N. Barger; Robert T. Merrick [57] ABSTRACT A container for sterile medical liquids that has a double cap sealed closure system. A deformable thermoplastic top wall of an outer cap is spaced a distance from a top wall of an inner cap when properly sterilized. Thumb pressure on the outer cap brings the top walls of the two.caps into contact. This contact provides an instant tactile test for determining that the References Cited container has been through a steam sterilization cycle UNITED STATES PATENTS and there are no leaks at the inner and outer cap seals with the bottle. 2,040,798 5/1936 Schoonmaker 215/37 R 2,851,201 9/1958 Poitras 2l5/DlG. 3 8 Claims, 6 Drawing Figures THUMB Id/E US. Patent Dec. 2, 1975 Sheet 1 of 3 3,923,179

Bra 2.

THU/W5 65306 sheet 2 on 3,923,179

US. Patent Dec. 2, 1975 U.S. Patent Dec. 2, 1975 Sheet 3 of3 3,923,179

mun/w g/aeaasuee ew BACKGROUND Sterile medical liquids such as normal saline, dextrose, sterile water, etc., are often bottled and sterilized 'by manufacturersand then shipped to hospitals. The

bottles remain unopened until immediately ready to administer sterile irrigating liquids to a surgical wound or to give an intravenous feeding to a patient, etc.

It is highly c ritical to have a test to insure that the closed containershave been properly sterilized. Sterilization is often accomplishedby subjecting the closed seal containers to steam autoclaving at 240 to 260 F (116 to 127 C). When the bottles are of rigid glass they are often evacuated and utilize a thin rubber disc over an opening in the container outlet as a sterility indicator. The evacuated interior of the bottle creates a visual dimple in the rubber disc for indicating the integrity of the bottle seals and sterility of the contents.

However, when a semi-rigid or collapsible thermoplastic bottle or bag is used for storing anddispensing the sterile medical liquids evacuation is not practical. Evacuation of such thermoplastic containers that have an airspace above the liquid would cause such containers to collapse. Therefore it is necessary to provide an indicator that shows the bottle has been through the autoclav'e and also that the closure seals are intact. This invention'r'elates to such asterility indicator for a nonevacuated sterile medical liquid container.

. SUMMARY OF THE INVENTION This invention provides a special double closure system for a non-evacuated thermoplastic container for sterile medical liquids. This closure system has an inner closure that hermetically seals off a dispensing neck. This inner closure can be either a screw cap as in a pouring container or a transverse coupling head for connecting to an intravenous administration set. Fitting over this inner closure is a thermoplastic cap that is hermetically sealed to the thermoplastic container. There is a small controlled volume of air sealed between the inner closureand outer cap which are spaced a small distance from each other. I

After the container and closure system has been subjected to steam sterilization temperatures and pressures and cooled to room temperature, the outer cap is permanently deformed but has a top ,wall that remains spaced from the inner cap. Thumb pressure on the centerof the outer cap top wall will bringthis top wall into contact with the top wall of the inner closure. When this is done there is-a springy feel to this deflection of the outerlcaps top wall. This is' because of the small volume of sealed air space between the outer cap and the inner closure, and the relief of molded in stresses by the sterilization cycle. When. an operator feels this springback characteristic of the outer cap this indisterilization be discarded.

THE DRAWINGS FIG. 1 is a front elevational view of the sealed container as it is shipped and stored ready for use;

FIG. 2 is an enlarged sectional view taken vertically through the closure system of a first embodiment of the closure system with'inner' screw cap, showing the outer cap after sterilization when both the inner cap seal and outer cap seal are intact;

FIG. 3 is an enlarged sectional view showing the outer cap structure of FIG. 2 after sterilization when there has been a leak in the outer cap seal;

I FIG. 4 is an enlarged sectional view showing the outer cap structure of FIG. 2 after sterilization when there has been a temporary inner closure seal failure;

FIG. 5 is an enlarged sectional view of a second embodiment showing the outer cap combined with an inner closure adapted for connecting to an administration set for intravenously feeding a patient; and

FIG. 6 is a front view of the thermoplastic container with the inner closure of FIG. 5 connected to a medical administration set.

DETAILED DESCRIPTION Referring to these drawings the thermoplastic container is shown generally as l in FIG. 1. This container has a base 2 with an indented hanging tab 3 for supporting the container in a mouth downward position, such as the administering intravenous solutions. At a top of the container is a dispensing neck 4 and a closure system generally indicated as 5. This container contains sterilemedical liquids such as 5% dextrose, normal saline, sterile water, etc., and is supplied to the hospitals as shown in FIG. 4.

This special closure system is shown in more detail in FIG. 2. Here the bottle 1 in a first embodiment is used as a pouring container. Its sterile liquid contents are poured from dispensing neck 4 such as to flush a surgical wound, etc. The pouring container neck 4 terminates in a pouring lip 6. I-Iermetically sealing off the pouring neck 4 and lip 6 is an inner cap 7, with a top wall 8 and a skirt 9. Skirt 9 and neck 4 have intermeshing threads which squeeze a deformable sealing rib 10 down against dispensing lip 6 to form a hermetic seal at the inner closure.

Fitting over the inner closure and neck of the bottle is an outer closure generally indicated at 1 1. This outer closure has a top wall 12 and a depending skirt 13. At a bottom end of skirt 13 is a lateral extending frangible brim 14. This brim is heat fused at an annular hermetically sealed joint at 15. In FIG. 2 the outer cap and inner closure are very closely spaced together and define a sealed small volume air space 17. The important top wall 12 of the outer cap 11 is generally flat immediately prior to sterilization and includes a series of concentric internal blocking ribs 18 and 19. Prior to sterilization the bottom surfaces of the blocking ribs 18 and 19 are approximately 0.020 to 0.080 inches (0.51 to 2.1 millimeters) from the top surface of wall 8 of the inner closure. When the liquid filled container and closure systems are subjected to sterilization temperatures of from 240 to 260.F. (116 to 127 C.) at pressures of 35m 38 psi (24 to 27 gmJmmF), the thin thermoplastic top wall that is 0.015 to 0.040 inch thick (0.38 mm. to 1.04 mm.) is pushed down against the top wall 8 of the inner closure. When this happens, the top wall deforms into a' series of concentric depressions between the blocking ribs 18 and 19. This gives a visual 3 indication that the container has been through the sterilization cycle. Steam sterilization also relieves certain molded in stresses in the outer cap that alters the physical characteristics of the outer cap.

After the container has cooled to room temperature the top wall 12 of the outer cap 11 lifts of the inner closure 's top wall 8. This leaves a small distance or gap between the blocking ribs 18 and 19 and the top wall 8 of the innder closure. It has been found that this distance after sterilization ranges from 0.030 to 0.060 inch (0.76 to 1.5 millimeters).

Thumb pressure as shown at FIG. 2 at the center of top wall 12 of the outer closure 11 pushes the thin deflectable top wall downwardly until the blocking ribs 18 and 19 contact the top surface of the top wall 8 of the inner closure. This contact between the two closures can be physically felt. Release of the thumb pressure causes the top wall 12 to spring back to its normal position shown in FIG. 2. This provides a tactile test for checking that there is no leak and the container has been through the sterilization cycle.

When there is an outer cap leak, a permanent inner cap leak, or a temporary inner cap leak, the manner in which the outer cap reacts to pressure will indicate these different types of seal failure. These will be explained as follows:

a. Outer Cap Leak. If there is a leak in the outer cap seal, the top wall of the outer cap will be sucked down against the inner closure and will not yield to thumb pressure (FIG. 3).

b. Permanent Inner Closure Leak. When there is a permanent inner closure leak such as a broken portion of sealing rib 10, the outer cap gives both a visual and a tactile indication of this. Visually the outer caps top wall appears generally as it did before sterilization. The annular depressed areas between ribs 18 and 19 are shown in FIG. 2, are not present when there is a permanent inner cap leak. Tactically thumb pressure on the outer caps top wall lacks the springy return from contact with the inner cap. This is because pressure is equalized between the two caps and the bottle's interior. Since the bottle has an air space above its liquid contents that is many times greater than the volume between the two caps, the bottle acts as a large volume air reservoir communicating with the space between the two caps. This air reservoir is at approximately atmospheric pressure and pushing the outer caps top wall into contact with the inner caps top wall causes insignificant compression of air between the caps.

. Temporary Inner Cap Leak. When there is a temporary leak at the inner cap that has subsequently resealed the outer caps top wall takes on an outwardly bulged configuration as shown in FIG. 4. This situation would occur when there was a very slight leak at sealing rib prior to sterilization. During sterilization pressures within the bottle would build up as the bottle is steam autoclaved at 240 to 260 F. After steam sterilization, cooling of the container and closure system of FIG. 4 causes sufficient shrinkage of the inner cap to reseal rib 10 against the bottle neck. High pressure air then becomes trapped between the two caps. When the container is removed from the autoclave the overriding pressure external of the bottle that is present during sterilization is no longer surrounding the 4 bottle. Therefore the outer cap bulges up as shown in FIG. 4. I

In summary the three conditions mentioned in a, b, and c above, give an indication not only that the bottle is defective but also what kind of defect is present.

In the first four drawings shown in the application, the inner closure has been shown as a screw cap which can be removed for pouring out the liquid contents of the thermoplastic bottle. To gain access to this inner screw cap, the outer cap which is hermetically sealed to the container must first be removed. One method of removing this outer cap is with a jacking ring 20. This jacking ring intermeshes with external threads on the outer cap skirt 9. This jacking ring, explained in our copending United States application entitled Double Screw Cap System for Sterile Medical Liquid Container and Method of Opening Same, Ser. No. 3 38,671, fractures the outer cap at an annular frangible section 21.

Once removed the outer cap exposes the inner screw cap which can be physically unscrewed from the bottle neck and the liquid contents poured into a surgical wound or the like.

In FIG. 5 a second embodiment of the invention is shown. Here the outer cap 25 is identical to the outer cap 1 l of FIG. 2. However, the inner closure 27 in FIG. 5 is different. This inner closure has a transverse top wall 28 and a short depending skirt 29 or other means which is permanently bonded or fused to the dispensing neck 30 of the FIG. 5 embodiment. Located within transverse wall 28 is a puncturable diaphragm 31 and a surrounding sleeve 32. After the outer cap has been removed a puncturing spike from an administration set can puncture diaphragm 31 and be gripped by sleeve 32. This type structure of the entrance port for coupling with an administration set is shown schematically and other type connections can be employed. Also, if desired, the transverse wall 28 can include a resilient or rubber puncturing pad 33 for injecting additive medications.

In the second embodiment shown in FIG. 5 the thermoplastic container 34 is shown hanging in a mouth downward position from a hanging tab 35. The outer cap has been removed and a puncturing spike of an administration set 35 has been inserted through the inner closure.

The tactile sterility indicator operates the same in FIG. 5 as it does in FIG. 2. Likewise a threaded jacking ring 37 can be used to break apart the outer cap 26.

The tactile sterility indicator of the double closure system of this invention works exceptionally well when the outer cap is injection molded of a propylene ethylene copolymer theremoplastic material and the bottle is likewise of a propylene ethylene copolymer theremoplastic material. These copolymers, called pollyallomers, are marketed by Eastman Chemical Company under the name TENITE. This material provides an easily controllable fusion joint at the fracture point of the outer cap and also top wall of the outer cap is permanently deformable at steam sterilization temperatures and pressure. The jacking ring can be of a rigid theremoplastic, thermosetting, or metal material.

In the foregoing specification specific embodiments have been used to describe this invention. However, those persons skilled in the art will understand how to make certain modifications to these embodiments without departing from the spirit and scope of the invention.

We claim:

1. A container with inner and outer closure for storing and dispensing sterile liquids, which includes a blow molded thermoplastic container with a dispensing outlet, and the container and outer closure forming a unit that has a transverse abutment means surrounding the outlet wherein the improvement comprises:

the inner closure secured to the container to close off the outlet and form a hermetically sealed enclosure, said inner closure having at least a portion that is openable for dispensing; and a separately formed thermoplastic outer cap with a longitudinal axis, which outer cap is hermetically sealed to the enclosure with a bacteria-tight bound proximate said abutment means, said outer cap having a manually deflectable top wall physically spaced a predetermined distance from the inner closure so that said wall can be deflected a sufficient amount by thumb pressure to cause the outer cap and inner closure to contact each other for a tactile determination of the integrity of the outer cap and inner closure; and said outer cap has both a thin frangible section proximate said abutment means and externally exposed threads with the threads of the outer cap being in a axial alignment with the abutment means, whereby said threads can receive a threaded opening member and guide it toward the abutment means for exerting a pressure against the abutment means to axially pry the outer cap apart at its frangible section.

2. The combination as set forth in claim 1 wherein the outer caps top wall has at least one blocking rib extending inwardly from an inner surface of said top wall.

3. The combination as set forth in claim 2 wherein there are a plurality of concentric rings of blocking ribs extending inwardly from an inner surface of the outer caps top wall.

4. The combination as set forth in claim 1 wherein there is an internally threaded jacking ring threadingly disposed on the outer cap for rupturing the cap by exerting an axial force between the outer cap threads and the abutment means.

5. The combination as set forth in claim 1 wherein the outer cap has a deflectable top wall sufficiently flexible so as to balloon up into a visible crown when there is a temporary leak that has rescaled between the inner closure and the container and the unit is sterilized at 240 to 250 F. at 35 to 38 psig.

6. The combination as set forth in claim 1 wherein the outer cap has a top wall sufficiently thin so as to permanently deflect and deform into permanent contact with the inner closure upon a leak in the outer closure, and the unit is sterilized at 240 to 260 F. at 35 to 38 psig.

7. The combination as set forth in claim 1 wherein the outer cap has a top with a wall thickness of 0.015 to 0.040 inch.

8. The combination as set forth in claim 1, wherein the deflectable portion is spaced 0.030 to 0.060 inch from the inner closure.

i l l l l 

1. A container with inner and outer closure for storing and dispensing sterile liquids, which includes a blow molded thermoplastic container with a dispensing outlet, and the container and outer closure forming a unit that has a transverse abutment means surrounding the outlet wherein the improvement comprises: the inner closure secured to the container to close off the outlet and form a hermetically sealed enclosure, said inner closure having at least a portion that is openable for dispensing; and a separately formed thermoplastic outer cap with a longitudinal axis, which outer cap is hermetically sealed to the enclosure with a bacteria-tight bound proximate said abutment means, said outer cap having a manually deflectable top wall physically spaced a predetermined distance from the inner closure so that said wall can be deflected a sufficient amount by thumb pressure to cause the outer cap aNd inner closure to contact each other for a tactile determination of the integrity of the outer cap and inner closure; and said outer cap has both a thin frangible section proximate said abutment means and externally exposed threads with the threads of the outer cap being in a axial alignment with the abutment means, whereby said threads can receive a threaded opening member and guide it toward the abutment means for exerting a pressure against the abutment means to axially pry the outer cap apart at its frangible section.
 2. The combination as set forth in claim 1 wherein the outer cap''s top wall has at least one blocking rib extending inwardly from an inner surface of said top wall.
 3. The combination as set forth in claim 2 wherein there are a plurality of concentric rings of blocking ribs extending inwardly from an inner surface of the outer cap''s top wall.
 4. The combination as set forth in claim 1 wherein there is an internally threaded jacking ring threadingly disposed on the outer cap for rupturing the cap by exerting an axial force between the outer cap threads and the abutment means.
 5. The combination as set forth in claim 1 wherein the outer cap has a deflectable top wall sufficiently flexible so as to balloon up into a visible crown when there is a temporary leak that has resealed between the inner closure and the container and the unit is sterilized at 240* to 250* F. at 35 to 38 psig.
 6. The combination as set forth in claim 1 wherein the outer cap has a top wall sufficiently thin so as to permanently deflect and deform into permanent contact with the inner closure upon a leak in the outer closure, and the unit is sterilized at 240* to 260* F. at 35 to 38 psig.
 7. The combination as set forth in claim 1 wherein the outer cap has a top with a wall thickness of 0.015 to 0.040 inch.
 8. The combination as set forth in claim 1, wherein the deflectable portion is spaced 0.030 to 0.060 inch from the inner closure. 